2.7i Stroker Balancing

[5KWattson]

is it really worth it to balance my stroker build let me explain how im building it


stock 2.7 crank, rods and pistons with around 180k on them in my i block with my i head and i have a chip for the ecu along with a ceramic 6 puck clutch im also going to do some mild gasket matching on the intake and exhaust the head and manifolds.

but i am to the point were i can put it together unbalanced or go spend about 230-280 and get the entire rotating assembly balanced...so any feed back would be great

im also awere the lower compression im going to have so i might add a ct36 off a 3rd gen supra soon

[Jparkr]

You are using regular eta pistons? then yeah your compression will be low.

When I did my engine the machine shop was told to balance everything, but they didn't.

All in all, I would recommend doing it, but it isn't necessary since i've been driving my car for a while without it being balanced.

[jlevie]

Balancing of the rotating parts is less important than equal deck height and equal chamber volume if you are using all OE parts for the crank, rods, and pistons. It won't hurt to have everything balanced, but the benefit is out weighed by the cost.

[5KWattson]

thats kinda what im thinking, i just needed some outside views, well what about the flywheel do you think that its worth it to lighten up that heavy i chunk of metal

[nando]

eh, it's not like BMW builds motors like an 80's GM product, they are pretty decent from the factory already. If you are building an all out race motor that will see heavy track duty, sure, but for just a street/weekend fun car, it's probably not worth it.

[a_thomasmr23]

for the money its not worth it the weight difference that BMW holds their parts to is nut really. The bentley put the pistons at +/- 2 grams and the rods are about the same. VW on the other hand i've had a set of OE pistons that where +/- 8 grams and they where fine in 170k motor

[StereoInstaller1]

Balancing an I-6 is far less important than balance on any V engine.

[5KWattson]

thanks i called the machine shop and told them im just going to lighten the flywheel and put it back together i kinda figured bmw has there shit together i just didnt know if it would be 2worth it or not...like i said they are talking 230-280 to balance it but i think i can use that money else were and gain more hp on a diff afm or somthing

[robmespeedy]

do it right! balance it.

[Madhatter]

this is a moot point for me, why? because if you place a crank in another block (that it didnt come out of), you should have the mains line bored. If you have that done, its no big deal to have it balanced. Its done when the motor was put together, so why shouldnt it be done now that you are swapping the bottom end out.

Ill never swap cranks and bottom ends without having the above done, at least you get an engine with less harmonics and a few extra hundred rpm at the top end, at the most you fix a whole host of issues that can see you spin a bearing or sieze an engine.